Our staff sets the expected daily lineups 24-30 hours before tip-off. The expected lineups are then tweaked throughout the day of the game.
Lineups are only confirmed when an official NBA source provides that information.
Unfortunately, the NBA does not require that starting lineups be submitted before tipoff, which is why we are sometimes limited to waiting until a game tips off to accurately pass on who is starting for some games. Also, sometimes players are "scratched" at the very last minute.
If a player has a color bar next to his name, that reflects some level of uncertainty about whether he'll be active for the game. Most players have a color bar when dealing with an injury, but we will also add estimates if a player's status in doubt due to rest or other off-court issues.